Lesson selector element controlled device for presenting visual and audio lessons and receiving recorded answers on a sound track

ABSTRACT

A device for teaching a multiplicity of students the same subject matter or different subject matter on each of a plurality of machines, by presenting these in visual and audio form, asking pertinent test questions and receiving the answers on a sound track, such as a removable cassette tape, to enable the teacher to evaluate the progress of the student in the subjects being studied. A lesson selector element is utilized for each lesson to be taught. The lesson selector element automatically sets or resets the machine to the particular lesson to be taught. The lesson selector element thus teaches the lesson for a predetermined number of minutes, when the visual and audio portions are cut off, at which time a signal is given the student to answer or to recite answers to questions relative to the particular material taught, and to automatically stop and reject the lesson selector element, after the recorded material has been properly identified on the sound strip by indicia. The teacher may thus evaluate the answers in accordance with the subject matter exposed to the student.

United States Patent [1 1 Streit [76] Inventor: James L. Streit, Rt. 3,Box 364,

Vernon, Tex. 76384 [22] Filed: July 17, 1972 [2]] Appl. No.: 272,641

[52] U.S. Cl. 35/8 A, 353/15 [51] Int. Cl. G09b 5/06, G03b 31/06 [58]Field of Search 35/8 A, 35 C;

[56] References Cited UNITED STATES PATENTS l/l97l Stapleton 35/8 A UX12/1969 Dorsett 7/1971 DeBell et ill. 35/8 A Primary ExaminerWm. H.Grieb Attorney-Wayland D. Keith [451 Jan. 1, 1974 [5 7] ABSTRACT Adevice for teaching a multiplicity of students the same subject matteror different subject matter on each of a plurality of machines, bypresenting these in visual and audio form, asking pertinent testquestions and receiving the answers on a sound track, such as aremovable cassette tape, to enable the teacher to evaluate the progressof the student in the subjects being studied. A lesson selector elementis utilized for each lesson to be taught. The lesson selector elementautomatically sets or resets the machine to the particular lesson to betaught. The lesson selector element thus teaches the lesson for apredetermined number of minutes, when the visual and audio portions arecut off, at which time a signal is given the student to answer or torecite answers to questions relative to the particular material taught,and to automatically stop and reject the lesson selector element, afterthe recorded material has been properly identified on the sound strip byindicia. The teacher may thus evaluate the answers in accordance withthe subject matter exposed to the student.

14 Claims, 32 Drawing Figures PATENTEB JAN H974 3.782.007,

SHEET U3UF11 sum 10 HF 11 PATENTEU JAN 1 4 vmm fi wmm www T 1LESSON'SELEC'IOR ELEMENT CONTROLLED DEVICE FOR' 'PRESENTING VISUAL ANDAUDIO LESSONS AND RECEIVING RECORDED ANSWERS ON A SOUND TRACK"BACKGROUND OF THE INVENTION to-give'independentvisual and audioteaching on each subject for a predetermined length of time and permitthe answers to be given, either wholly through audio recording or acombination of audio recording and graphic answers. In general,-knownmachines are complex, expensive in'construction and not readily subjectto be reprogrammed for each student, without extensive replacement ofthe data systems.

2. Summary of the Invention The presentteaching machine'contemplatesthepresentation of information by visual film and by sound producing means.The lessons are automatically brought into register when a lessonselector element or information retriever is placed in the machine,which will cause the retrieval o'f-one of a multiplicity of lessons,which could be on the order ofoneto 'twohundred or more,without'changing the master sound track on the machine. The master soundtrack maybe readily changed and indexed with the machine so it will comeinto proper register when the lesson selector element or lessonretrieverisputinto the machine, with the lesson selector elementproviding a 'portion of the lesson for visual analysis, while the soundprovides the balance of the lesson.

When the lesson is taught in accordance with the program lesson selectorelement or lesson initiator, which has been inserted into the machine, atime signal is given to enable the student to prepare to take a quiz.The quiz may be one question followed by an answer, several questionsfollowed by the several answers, or a series of questions, each followedby an answer. The answers are recorded on a sound receivinginstrumentality, such as a tape cassette recorder, a magnetic wirerecorder, which may be in cartridge form, or a phonographic disc orcylinder. Each of the recordings is properly identified by number orother indicia to enable the teacher to properly grade the materialsubmitted.

The present invention also contemplates, but is not restricted to, theuse of graphic sheets in combination with the lesson, whereby thestudent may draw or symbolize such questions as cannot be answeredphonetically, such as finger position on a musical instrument. Thecontrol of the machine is preprogrammed on the lesson selector elementor lesson initiator in such manner that, when certain functions areperformed, the teaching machine will move into another phase. Otherphases may be initiated, for example, by an audio switch or whistleswitch. However, the present device is not limited to such switches, butthe use thereof is pointed up, since. a sound track being played canprogram the proper sequence of operation of the machine.

An object of this invention is to provide a teaching machine which isall inclusive, to teach a subject. both visually and audibly and toreceive and record the answers to the preprogrammed subject matterwiththe use of such indicia that the answers may be readily cross checkedwith the questions in a minimum of time.

Another object of the invention is to provide a device which willautomatically index that portion of a lesson which is to be taught byaudio reproduction in complementary relation to a lesson selectorinitiator which contains that portion of the lesson which is to beprojected for visual use.

A further object of the invention is to provide a teaching machine whichwill teach for a predetermined period of time, at the end of whichperiod a signal will be communicated to the student, to alert thestudent to the beginning of an answer period, and to the fact that theanswers will be recorded for a predetermined length of time, therebyrecording the answers on readily accessible sound media, such as acassette cartridge.

Still another object of the invention is to provide a teaching machinewhich lends itself to teaching of various subjects by both visual andaudio means, such as band, modeling, poise, mechanics, and other artsand crafts which have heretofore required personal instruction in orderto be properly presented.

Yet a further object of the invention is to provide an electricallyoperated teaching machine which is selfcontained and which does notrequire the use of remotely positioned screens or speakers.

Yet another object of the invention is to provide a lesson initiatormodule which has initiating elements to actuate certain switches andcertain mechanical elements to bring the proper lesson into register,both on 'the lesson initiator and in the teaching machine.

Still another object of the invention is to provide a lesson initiatorwhich has a projectable film therein, which will automatically change todisplay a picture relative to the subject matter being taught and toprovide means for synchronously producing sounds that are compatiblewith the picture displayed,

Another object of the invention is to provide a lesson recording soundmeans which is synchronized and indexed with respect to the lesson beingtaught.

Still another object of the invention is to provide a lesson selectorelement controlled device which provides visual and audiblerepresentations in synchronization and with effeciency, effectivenessand reliability.

Yet another object of the invention is to provide a lesson selectorcontrolled device which may be utilized with facility and convenience byanyone to provide visual and audible representations in snychronism.

BRIEF DESCRIPTION OF THE DRAWINGS With these objects in mind and otherswhich will become apparent as the description proceeds, reference is tobe had to the accompanying drawings, in which like reference charactersdesignate like parts in the several views thereof, in which:

FIG. 1 is a perspective view, with parts broken away, of an embodimentof the lesson selector element or preprogrammed, controlled teachingmachine;

FIG. 2 is a side view of the teaching machine of FIG. 1, with the rightside removed, and with parts shown in section to bring out the detailsof construction;

FIG. 3 is a perspective view of the magnetic tape reel drive of thestereo tape recorder of the teaching machine taken along the line 3-3 ofFIG. 16;

FIG. 4 is a view, partly in section, taken on the line 4-4 of FIG. 16,showing a counter belt of the teaching machine;

FIG. 5 is a view, partly in section, and on an enlarged scale, of thecontact arrangement as shown in FIG. 4;

FIG. 6 is an end view taken on the line 6-6 of FIG. 5, looking in thedirection indicated by the arrows;

FIG. 7 is a sectional view, with parts shown in elevation, taken on theline 77 of FIG. 16, looking in the direction indicated by the arrows,showing a counter belt of the teaching machine;

FIG. 8 is a view, mostly in section, taken on the line 8-8 of FIG. 16,looking in the direction indicated by the arrows;

FIG. 9 is a view, partly in section, taken on the line 99 of FIG. 16,looking in the direction indicated by the arrows; and showing anothercounter belt of the teaching machine;

FIG. 10 is an enlarged sectional view, taken on the line 10-10 of FIG.9, looking in the direction indicated by the arrows;

FIG. 11 is a view, partly in section, taken on the line 1l-l1 of FIG.16, looking in the direction indicated by the arrows; and showinganother counter belt of the teaching machine;

FIG. 12 is a side view, partly in section, on an enlarged scale, showingthe contact arrangement of the device, as shown in FIG. 11;

FIG. 13 is a sectional view taken on the line 13-13 of FIG. 12, lookingin the direction indicated by the arrows;

FIG. 14 is a front view ofthe stereo tape recorder of the teachingmachine, taken on the line l414 of FIG. 16;

FIG. 15 is an enlarged fragmentary longitudinal sectional view ofthesequence switch as shown in FIG. 32;

FIG. 16 is a front elevational view ofthe teaching machine, with partsbroken away, and with parts being shown in section to bring out thedetails of construction;

FIG. 17 is a view, partly in section, ofthe solenoid arrangement, takenon the line 17 17 of FIG. 19, looking in the direction indicated by thearrows;

FIG. 18 is a view, partly in section. showing the tension spring of thedetent arrangement of FIG. 19;

FIG. 19 is a view. partly in section, of the detent arrangement of theteaching machine. taken on the line 19-19 of FIG. 16, looking in thedirection indicated by the arrows;

FIG. 20 is a fragmentary exploded perspective view ofthe drive shaftarrangement as shown in FIGS. 3 and 16;

FIG. 21 is a sectional view taken on the line 21 21 of FIG. 16, lookingin the direction indicated by the arrows, with portions being shown insection and with portions being broken away to show the details ofconstruction;

FIG. 22 is a view of part of a lesson selector element of the teachingmachine;

FIG. 23 is a view of part of another lesson selector element of theteaching machine, but showing it programmed for a different lesson;

FIG. 24 is a sectional view taken on the line 24 24 of FIG. 16, lookingin the direction indicated by the arrows;

FIG. 25 is a sectional view taken on the line 25 25 of FIG. 24, lookingin the direction indicated by the arrows, showing the conductors andguide arrangement of the teaching machine;

FIG. 26 is a top perspective view of the lesson selector element, whichhas a portion of the lesson thereon;

FIG. 27 is a bottom perspective view of the lesson selector element, asshown in FIG. 26, with portions being broken away and shown in section,to bring out the details of construction;

FIG. 28 is an exploded view, partly in section and partly inperspective, of the lesson selector element, as shown in FIGS. 26 and27; taken on the line 28 28 of FIG. 27, looking in the directionindicated by the arrows;

FIG. 29 is an enlarged top plan view, with parts broken away and withparts shown in section, of the photographie slide arrangement of thelesson selector of the teaching machine;

FIGS. 30, 31 and 32, when arranged in sequential relation, constitute adiagram of the electrical circuit of the teaching machine.

DETAILED DESCRIPTION OF THE INVENTION The lesson selector element of thepreprogrammed teaching machine provides a means of presenting any one ofa plurality of lessons, without the necessity of a teacher beingpresent. Each of the lessons is coordinated with respect to sight andsound, as hereinbefore described, means is also provided to record thereactions of the students to certain parts of the lesson and to recordthe students answers to any question which the instructor may deemnecessary. The instructor is thereby provided with a basis for assessinga grade to the student's lesson.

The outward appearance of the teaching machine somewhat resembles atelevision set. A suitable cabinet is provided to house the operatingelements of the machine, and a screen is provided in the front of thecabinet. The visual portion of the lesson is projected onto the acreen.A suitable speaker is also located directly behind a grid or cover infront of the cabinet. The sound or audio portion of the lesson isemitted through the speaker. An additional opening is provided in thefront of the cabinet, which opening is provided with a suitable cover orgrid, the sound of the students response passes through the opening andis picked up by a microphone which is located directly behind theopening. The microphone is connected to a cassette recorder placedinside the cabinet. A slot is provided in the front of the cabinet forthe purpose of receiving a laminated plastic lesson selector element.The purpose of the lesson selector element is hereinafter described. Alesson reject push button is also provided in the front of the cabinet,as will be more fully described hereinafter.

Suitable hinged access doors are provided on each side of the cabinet,for maintenance of the operating elements of the teaching machine, andan additional, smaller door is provided in the left hand access door, toprovide access to the cassette recorder. The teachingmachine'is'rendered tamper-proofby the'provision of flush-type locksonall the access doors.

The 'operatingtelements of the teaching machine are housed in the abovementioned cabinet. The operating elements consist essentially of astandard commercial stereo tape recorder with push button controls, twobanks of counter mechanisms, a set of'four flexible belts whicharedriven by the counter mechanisms,a set of four slidably mountedcarriages positioned directly above the flexible belts, a system ofrelays and solenoids for operating the push buttons on the taperecorder, a speaker, mentioned above, a Magic Lantern"typeoftphotographis slide projector with a suitable system of lenses andreflectors for projecting an image on .a screen of the above mentionedtype, a cassette recorder, above mentioned, a second system of relaysand solenoids for operation of the push button on the cassette recorder,an'electromechanical mechanism for selecting a'photographic image to-beprojected on the screen in a manner that will be described more indetail 'hereinafter, a second electromechanical mechanism for locking ina laminated plastic lesson selector element and for ejecting the lessonselector elementat the completion of'the lesson,-and the necessarywiring for'the aforementioned elements. A set of three whistle switchesare also included for apurpose, as will be more fully set outhereinafter. A whistle switch is a relay which is sensitive to anultrasonic signal.

An essential :part of the present device is a'set of 'laminated gplasticlesson selector elements, there being a separate element-foreach lesson.Eac'h of'the lesson selector elements contains a rotatabled'isc'equipped with a series of photographic transparencies for use withthe slide projector in the machine. The lesson selector elements arealso provided with a series of projections which engage correspondingprojections on the carriages, for the purpose of positioning thecarriages which, in conjunction with the system or relays, solenoids,etc., operate the push but-tons on the tape recorder in such manner thatthe desired lesson stored in the tape of the tape recorder is selectedand played. During the course of the lesson, a series of ultrasonicsignals of three different frequencies is superimposed on the contentsof the program of each lesson.

Each of the whistle switches is tuned to one of these frequencies andignores the other two. One of the whistle switches is connected to themechanism which rotates the disc containing the photographictransparencies. The second whistle switch is connected to the mechanismwhich turns the cassette recorder on and off. The third whistle switchis connected to the solenoid which operates the linkage to release thelesson selector element at the end of the lesson. In addition to thesolenoid-operated linkage for ejecting the lesson selector element atthe end of the lesson, the aforementioned push button is provided toreject the card at any time after it has been inserted and locked inplace.

The operation of the teaching machine during any one lesson or programcan best be described-by referring to two separate and distinct cyclesof operation, the first of which is selection," and the second of whichis the play" cycle.

First, the function and operation of the various members are describedin the sequence of their activation during the normal operation of themachine.

The laminated lesson selector element corresponding to the desiredlesson is first selected and inserted into the machine which isdesignated by the numeral 1, through the slot -1A formed in the front ofthe cabinet, FIG. 1. As the lesson selector card 2, FIGS. 26, 27 and'28, is inserted into the machine 1, a latch 4, FIG. 8, is raised by aprojection 6 of the lesson selector element 2. Raising the latch 4rotates a shaft 8 and a crank 10, FIG. 2. This causes translation oflink 12, resulting in thecounter-rotation of a crank 14, a shaft 16 andan arm 18, thus depressing a plunger 20, FIGS. 2 and 8, against thepressure ofa spring 22, to allow the bottom of the lesson selectorelement 2 to pass over the top of the plunger 20. 7

Each lesson selector element 2 has a set of downwardly extendingprojections 24, 26, 28 and 30, FIG. 27. The projections '24 are sodisposed on each lesson selector element 2 that the projections 24 and28 are the same distance from the front of the lesson selector elementand the projections 26 and 30 are the same distance from the front ofthe lesson selector element. However, the projections 24 and 26 or 28and 30 are not necessarily equal distances from the front of the lessonselector element. The projections 24, 26, 28 and 30 engage correspondingupstanding projections 32, 34, 36 and 38, of the respective carriages40, 42, 46 and 48, FIGS. 11, 9, 7 and 4, respectively.

As the lesson selector element 2 is pushed into the machine on thetracks or guides 238 and 248, FIGS. 11, 1'6, 21, 24 and 25, theprojections 24, 26, 28 and 30, FIG. 27, engage the respectiveprojections 32, 34, 36 and 38, FIGS. 11, 9 and 4, thereby causing thecarriages 40, 42, 46 and 48 to move along the respective tracks orguides until the lesson selector element 2 is fully inserted. When thelesson selector element 2 is fully inserted, the carriages are in apredetermined location, depending upon the disposition of theprojections 24, 26, 28 and 30 on the lesson selector element.

With the lesson selector element fully inserted, the projection 6, FIGS.8, 21, 31 and 32, will clear the latch 4, thus permitting the spring 22to urge the plunger 20 up through the hole provided in the lessonselector element 2. Through the linkage 8, 10, 12, 14, 16 and 18, thelatch 4 is forced down behind the projection 6, thus locking the lessonselector element 2 in place.

When fully inserted, the lesson selector element 2 also closes thecontacts of a power switch 50 and, depending upon the location ofcutouts 52 or 52A, FIGS. 22 and 23, if used, closes the contacts ofstereo channel selector switches 54 or 56, or both, FIGS. 21 and 31.

A standard stereo tape recorder 58 may be of any well known type, suchas may be purchased on the open market. The basic control of the taperecorder 58 is by means of push buttons 60, 62, 64 and 68, which arerespectively for Stop, Play, Rewind and Forward. A tape 70, FIG. 14, iscarried on reels 72 and 74, which reels are also standard commercialproducts.

The tape is not completely removed from the reel 72, so that any pointon the tape can be located by counting revolutions of the reel 72 fromsome index point, which could be regarded as the beginning of the tape.The counting of the revolutions of the reel 72 is done mechanically bymeans of two banks of counters 219 of the interrupted gear type.

Referring to FIGS. 3 and 16, it will be seen that the counters aredriven from the reel 72 by means ofa shaft 76, a coupling 78, a shaft80, a drive gear 82, idlers 84 and 86, and driven gears 88 and 90. Thedriven gear 88 drives a slotted disc 92, which disc is provided withtooth-like projections 94. The projections 94 then drive teeth 98 of apinion 96. The pinion 96 is provided with four teeth 98, which teeth arethe full width of the pinion 96, and with an additional four teeth 100which are approximately one-half the width of the pinion. The eightteeth of the pinion 96 drive a gear 102 which is rigidly connected to aslotted disc 104. The disc 104 is provided with tooth-like projections106 which engage the teeth ofa pinion 108 in the same manner as theprojections 94 engage the teeth of the pinion 96. The pinion 108 drivesa gear 110 in a manner identical to that by which the pinion 96 drivesthe gear 102.

One full revolution of the driven gear 88 results in one-fourthrevolution of the pinion 96, which in turn, results in one-tenthrevolution of the gear 102. The gear 102 may, therefore, be referred toas the units counter. Likewise, one revolution of the gear 102, or unitscounter, results in one-tenth revolution of the gear 110, which may thenbe referred to as the tens counter. The gear 110, or tens counter, isrigidly connected to a drum or sprocket 112, FIGS. 3 and 11, which inturn is rigidly connected to another slotted disc 114. The slotted disc114 is identical to the slotted discs 92 and 104. The drum or sprocket116, FIGS. 6 and 16, is driven through a pinion and gear arrangementwhich is similar to pinion 96 and gear 102 or pinion 108 and gear 110,to act as the hundreth counter.

The idler 86 is identical to the idler 84 and is rigidly connected to itby means of a shaft 118, FIG. 16. The idler 86 drives the gear 90, whichgear is identical to the gear 99. The second bank of counters is drivenby the idler 86, gear 90, and a system of slotted discs and pinions, ina manner identical to that just described, so that a gear 120 acts andthe units counter, and drums or sprockets 122 and 124 act as the tensand hundredths" counters, respectively.

The tens counters, sprockets 112 and 122, and the hundredths counters,sprockets 116 and 124 are provided with belts 126, 150, 128 and 130,respectively, as shown in FIGS. 2, 4, 7, l1 and 16. The belts 126, 150,128 and 130 are identical, and each is ofa length equal to three timesthe circumference of the respective sprockets 112, 116 and 112 and 124,except the belt 150 and the sprocket 116 are wider than the othersprockets and belts, and the belt 150 has two sets of projectionsthereon, as will be fully brought out hereinafter. The belt 126, FIG.11, has three equally spaced projections 132 thereon, on the outersurface thereof, as seen in FIG. 11. An idler sprocket 142 is spacedfrom sprocket 112 so that the cog belt 126 is fitted in timed relationthereon and is held taut by a spring loaded journaled bearing.

The belt 150, FIGS. 9 and 24, has two sets of projections 152 and 154 oneach outer side thereof, which sets of projections are on the outer faceof the belt and are spaced apart one-third the length of the endlessbelt, with projections 152 being'distributed in the same manner as theprojections on the belt 126. The projections 152 and 154, which form aset, are spaced apart so that the distance between projection 152 andprojection 154 is the distance of one-tenth the circumference ofthedrum, as will be seen in FIGS. 9 and 24. An idler sprocket 144 is aspaced distance from sprocket 116 so as to mount cog belt 150 in timedrelation.

An idler sprocket 146 is journaled a spaced distance from sprocket 122,which sprockets have belt 128 fitted thereon in timed relation, FIG. 7.The belt 128 has three spaced apart projections 132B thereon, whichprojections are equally spaced in the same manner as the projections onbelt 126.

An idler sprocket is journaled a spaced distance from the sprocket 124,which sprockets have a belt fitted thereon in timed relation, FIG. 4.The belt 130 has three, equally spaced projections therearound. Correcttension is maintained on the belts by spring tensioned journals 134,136, 138 and which support rotating idlers 142, 144, 146 and 148, FIGS.7 and 4.

The slides or carriages 40,42, 46 and 48 are slidably mounted in tracksor guides 238,240,242,244,246 and 248, FIG. 25, directly above the belts126,150,128 and 130, respectively, in such manner that contact with theprojections 132, 152 or 154, 132B or 132A will cause electrical contactsl56,158,160,162,164,168 or respectively to close, as will be fullybrought out here inafter, FIGS. 11,9, 7,4, 30 and 31.

The tape 70 has a plurality of lessons or programs recorded thereon. Thepurpose of the flexible belts, counters and associated mechanisms, asdescribed above, is to determine the correct location of the tape tostart the desired lesson or program. As set out above,

this is accomplished by counting revolutions of the reel 72 from someindex point, which could represent the beginning of the tape.

Upon insertion of the lesson selector element 2, FIG. 31, the contactsof the power switch 50 are closed and the carriages 40, 42, 46 and 48have been located in their respective positions by the projections 24,26, 28 and 30 on the lesson selector element 2, FIGS. 8, 9, 24 and 27.The circuit 168A, FIGS. 30 and 31, which supplies power to the taperecorder 58, is then energized. At this time, a signal must be suppliedto the tape recorder 58 to determine whether the tape 70 is to beadvanced or rewound.

The signal to determine whether the tape is to be advanced or rewound isprovided by the combined action of the carriages 40 and 42, as follows.Referring to FIGS. 12 and 13, it will be seen that the carriage 40consists of a sliding member 170A which is a nonconductor ofelectricity. An electrical conductor 172 is embedded in thenon-conducting member 170A. The electrical conductor 172 connects acontact shoe 174 and the upper contacts 156 and 158. The bottom ofthesliding member 170A is bonded to an assembly consisting ofa conductor176, and two springs 178, which are also electrical conductors, a secondconductor 180, the lower contacts 156 and 158, and a second contact shoe182. A single runner 184, of non-conducting material, is bonded to thebottom of the second conductor 180.

Referring to FIG. 11, it is to be seen that a physical contact betweenthe runner 184 and one of the projections 132 on the belt 126 results inelectrical contact between either or both sets of contacts 156 and 158.It is also seen, FIGS. 12 and 13, that electrical continuity between theshoes 174 and 182 is provided, whether either or both sets of contacts156 or 158 are closed.

The carriage 42, which is best seen in FIGS. 9 and 10, is similar inconstruction and operation to the carriage 40, except the carriage 42has two sets of runners, springs, contact shoes, etc. The carriage 42also has four sets of electrical contacts, with two sets used inconjunction with each runner.

A sliding member 186, of the carriage 42, FIGS. 8

. and 10. is made of non-conducting material. Conductors 188 and l90,FIG. 10, are embedded in the sliding member.;l86 and provide electricalcontinuity between the upper contacts and the contact shoes. Theconductor'1'88 is connected to the upper contacts'160 and 162 and to ashoe 192. The conductor 190 is connected to the upper contacts 164 and166 and to a shoe 194. Conductors 196 and 198 are bonded to theunderside ofthe sliding member 186. The conductors :196 is fastened tosprings 200, to which springs the conductor 204 is attached, which inturn carries the lower contacts 160 and 162. A runner 206 is made ofinsulating material and is bonded to the conductor 204. A shoe 208 isaffixed to the conductorl'96. The conductor 198 carries springs 210, thelower ends of which springs are affixed to a conductor 214. Theconductor 214 carries the lower contacts 164 and 166. A shoe 2'16is'fastened'tothe conductor '198. A runner 218, ofinsulating material,is bonded to the conductor 214.

FIG. 30 showsa diagrammatic representation of the carriages 40 and 42.Referring to FIG. 30, it is to be noted that a physical contact betweenthe runner 206 and a projection "152 on the belt 150 results inelectrical contact between either or both sets of contacts 160 and 162,while physical contact between the runner 2'18 and a projection 154,also in belt 150, results in electrical contact between either or bothsets of contacts 164 and 166.

The disposition ofthe projections 132 on the belt 126 and of the:projections 152 and 154 on the belt 150 has been described above. Itshould be pointed out, however, that these projections are notnecessarily in the positions, as shown in the FIGS. The location ofthese projections is determined by the position of the Tape 70, andconsequently, the position ofthe belts 126 and 150 at the end of thelesson or program, when the machine was last in operation.

Referring to FIG. 14, it is to be understood that the direction ofrotation of the reels 72 and 74, during normal operation ofthe taperecorder 58, is counterclockwise, with the tape 70 feeding from the reel72 to the reel 74. The disposition of the gear 82, the idler 84 and thegear 88, FIG. 3, imparts rotation in the same direction(counterclockwise) to the belt 126.

Referring to FIGS. 9 and 11, it is to be noted that the projections 132,on the upper part of the belt 126, are at the tangent points of thebelt, as are the projections 152, on the upper part of the belt 150. Thelinear distance between the tangent points is equal to the circumferenceof the drums or sprockets 112 and 116, if the radius is measured to theoutside of the belts. The counters, as described above, are synchronizedwith a counter 219, FIG. 14, which is an integral part of the taperecorder 58. The positions of the belts 126 and 150, as shown in FIGS. 9and 11, are at the index points, so that the counter 219, FIG. 14, wouldread 000. The belt 126,,which may be referred to as the tens belt, movesin increments of one-tenth revolution of the drum 112, while the belt150, which may be referred to as the hundredths belt" moves inincrements of one-tenth revolution of the drum 116.

The location of the projections 24, 26, 28 and 30, on the lessonselector element 2, FIG. 27, is determined by the reading on the counter218, which is integral with the tape recorder 58, at the beginning ofthe desired lesson or program. The lesson selector element 2, when fullyinserted and locked in place by the latch 4, locates the position of thecarriages 40, 42, 46 and 48.

Referring to FIGS. 9 and 11, it is evident that the location of the leftend of the carriages 40 and 42 provides an indication of the location ofthe start of the desired lesson or program. If the projection 152 on thetop of the hundredth belt 150 is to the left ofthe carriage 42, the beltmust be rotated clockwise to reach the proper point, or the tape must berewound. If the projection 152 is directly under the left hand end ofthe carriage 42, but the projection 132, on the top of the belt 126, isstill to the left of the carriage 40, the tape must be rewound.

However, if the projection 152 is under the carriage 42 and theprojection 132 is under the carriage 40, or if both projections 152 and154 are under the carriage 42, the tape must be advanced. From theforegoing. it may be deduced that, regarding the carriages 40 and 42 andthe projections 152 and 154 on the belt 150, no physical contact betweenthe projections on the belts and the runners on the carriages 40 and 42or physical contact between one projection and one runner will result inrewinding of the tape 70, whereas physical contact between more than oneprojection and runners will result in the advancing of the tape to thedesired location.

Referring to FIG. 25, it will be seen that electrical conductors orrails 220, 222, 224, 226, 228, 230, 232, 234 and 236 are embedded innon-conductor tracks or guides 238, 240, 242, 244 246 and 248. Referringto FIGS. 30 and 31, it has already been established that the contacts ofthe switch 50 have been closed by the full insertion of the lessonselector element 2, which is locked-in place by the latch 4. The circuit168A, which supplies power to the tape recorder 58, has been energized.The switch 50 also energizes a circuit 250 to supply power to arectifier 252 which in turn supplies low voltage direct current to thevarious control circuits. A conductor 254 supplies low voltage directcurrent to the rails 220, 226 and 230. The rail 222 is connected by aconductor 256 to a relay 258. The rail 228 is connected by a conductor260 to a relay 262. The rail 224 is connected by a conductor 264 to arelay 266.

The foregoing circuits are completed by connecting the relays to aconductor 268 which acts as a common ground or return conductor. Theconductor 254 also supplies power to switches 270, 272 and 274. A switch276 is connected in series with a switch 270. A switch 278 is connectedin series with the switch 272. A switch 280 is connected in series withthe switch 274. A conductor 282 connects the switches 276, 278, and 280to a relay 284 which operates a switch 286. The switches 270 and 274 arecontrolled by the relays 258. The switches 272 and 276 are controlled bythe relay 266. The switches 278 and 280 are controlled by the relay 262.All the aforementioned switches are normally open unless actuated bytheir respective relays.

As explained above, physical contact between the belt projections, suchas 132, and the runners, such as 184, results in closing the contacts,such as 156 or 158, or both. The closing of these contacts results inthe completion of an electrical circuit from the conductor 254 throughthe rail 220, the shoe 182, the contacts 156 and l58,--or both, the shoe174, the rail 222, the conductor 256, the relay 258, thereby causing theswitches 270 and 274 to close. Likewise, a physical contact between theprojection 152 and the runner 206 results in energizing the relay 262,thereby closing the switches 278 and 280. A physical contact between theprojection 154 and the runner 218 results in the relay 266 beingenergized and the closing of the switches 272 and 276 by said relay.

It is obvious that, if no physical contact exists between any of thebelt projections and the runners of the carriages, the relays 258, 262and 266 remain deenergized and the switches 270, 272, 274, 276, 278 and289 all remain open, the relay 284 remains deenergized and a switch 286remains in the position shown in FIG. 30. It is also obvious that ifonly one physical contact is made, one of the relays becomes energized,resulting in the switches associated with such relay being closed.However, an examination of the arrangement of the switches 270 and 280discloses that these switches are arranged in a series of two switchesin such manner that two relays must be energized before the conductor282and the relay 284 may be energized. It therefore follows, that theremust be at least two physical contacts between the belt projections andthe corresponding carriage runners before the relay 284 is energized.

The stop button must be released before either the rewind button 64 orthe advance button 68 can be depressed. Obviously, as shown in FIG. 30,an armature 288 of solenoid 290 is normally forced against the stopbutton 60 by action ofa compression spring 292. When the rectifier 252'is energized, as described above, conductors 254 and 296 are energized,causing the solenoid 290 to become energized, with the circuit beingcompleted by the common ground or return conductor 268. When thesolenoid 290 is energized, the armature is drawn away from the button 60against the pressure of compression spring 292. The stop button 60 isthus released.

Conductors 298 and 300 are energized by the conductor 254 and theposition of the switch 286 determines whether the conductor 302 of theconductor 304 is energized. The action of the selector switches 270 to280 in energizing the relay 284 or permitting it to remain de-energizedhas been previously described. The position of the switch 286 iscontrolled by the relay 284. With the switch 286 in the position shownin FIG. 30, the conductor 302 and a solenoid 306 are energized, causingan armature 308 to depress the button 64. The circuit is completed bythe common ground 268. When the relay 284 is energized, the switch 286is moved to the position which energizes the conductor 304 and asolenoid 310, thereby causing an armature 312 to depress button 68. Thecircuit is again completed by the common ground 268.

When the above described circuits are completed or closed, the stopbutton 60 has been released and, depending on the disposition of theswitch 286, either the rewind button 64 or the advance button 68 hasbeen depressed, causing the tape 70 to be either advanced or rewound.The reel 72 rotates and the shaft 76, the coupling 78, the gear 82,etc., rotate with said reel. The counters, drums and belts rotate in thesame direction as the reel 72.

The operations, as described above, after full insertion of the lessonselector element 2 and the resulting closure of the switch 50, arepractically instantaneous, and constitute part of the selection cycle.

The second part of the selection cycle, which will be described more indetail hereinafter, involves, the second bank of sprockets or counters120, 122 and 124,

FIG. 16, and the carriages 46 and 48, FIGS. 7, 4 and 31.

The idler gear 86, FIG. 16, is identical to the idler gear 84 and isconnected thereto by shaft 118. The gear 90, which is driven by idlergear 86, is identical to gear 88, which is driven by idler gear 84. Thesprocket 122 rotates at the same time as the sprocket 112 and thesprocket 124 rotates at the same time as the sprocket 116. The belt 128,FIG. 7, and the projections 132B thereon operate in unison, the belt 126and its projections 132 also operate inunison. The belt 130 and itsprojections 132A operate in unison with belt 150 and the projections 152and 154 thereon. The belt 130 does not require an auxiliary set ofprojections, such as the projections 154 on belt 150.

As previously set out, the projections 24 and 28, on the lesson selectorelement 2, are located at equal distances from the front of the lessonselector element, and the projections 26 and 30 are also located atequal distances from the front of the lesson selector element. Asfurther disclosed, the locations of these projections is determined bythe location of the tape with reference to some index point, at thestart of the desired lesson or program. It therefore follows, that thelocation of the carriages 46 and 48, after being set by the projections28 and 30 on the lesson selector element 2, indicate the position orlocation of the tape 70 at the start of the desired lesson or program.

As shown in FIGS. 4, 5, 6, 7 and 31, the carriages 46 and 48 aresubstantially identical in structure. The carriage 46, as particularlyshown in FIGS. 7 and 31, has a leaf spring 316 mounted thereon, whichresiliently urges a roller 314 against the outer surface of belt 128,which spring 316 has an electrical contact point thereon, which togetherwith an electrical contact point on body 324, form a pair of electricalcontact points 168, which contacts 168 are closed when one of theprojections 1328 on belt 128 engages roller 314. A contact shoe 320 isformed on the end of leaf spring 316 on the carriage 46 and is incontact with rail 234.

The carriage 48 as particularly shown in FIGS. 4, 5, 6 and 31, has aleaf spring 316A mounted thereon, which resiliently urges a roller 314Aagainst the outer surface of belt 130. The spring 316A has an electricalcontact point thereon, which together with an electrical contact pointon body 324A, form a pair of electrical contacts 170, which contacts areclosed when one of the projections on belt engages roller 314A. Acontact shoe 322 is formed on the end of leaf spring 316A on carriage 48and is in contact with rail 236.

The body 324A on carriage 48 serves as a sliding member and is made ofnon-electrical conducting material in which are embedded bolts or screws326 having nuts 328 thereon, to bindingly engage the leaf spring 316A tobody 324A. The body 324A of carriage 48 has a projection 38 formedthereon, which projection 38 is engageable by the projection 30 on thelesson selector element 2, when the lesson selector element is movedinto the position as shown in FIG. 4.

Thecarriage 48 is shown more in detail in FIGS. 5 and 6, and, when takenwith FIG. 31, shows an electrical conductor strip 330A bonded to thelower part of body 324A, with the contact shoe 334 being connectedthereto by an electrical conductor rivet 336, as will best be seen inFIG. 5, to provide electrical continuity between the strip 330A and theelectrical conductor shoe 334, which shoe engages conductor rail 232.

As above mentioned, the carriage 46 is substantially identical withcarriage 48, with the contact 168 on carriage 46 Closing a circuit whenone of the projections 1328 on the outer surface of belt 128 engagesroller 314. The contact shoe 320 on carriage 46 is substantiallyidentical with shoe 322 on carriage 48 and serves the same purpose, andthe shoe 332 on carriage 46 is substantially identical with shoe 334 oncarriage 48 and engages the electrical conductor rail, FIGS. 7, 25 and31. The projection 28 on lesson selector element 2 engages projection 36on carriage 46, FIG. 7, to move the carriage along the rails to thedesired position.

FIGS. 4 and 7 show that, as the projections 132A on belt 130 orprojections 132B on belt 128 pass under the roller 314A or the roller314, respectively, electrical contact is made between the upper andlower contacts 170 on carriage 48 or the upper and lower contacts 168 onthe carriage 46, thus completing the circuit between the shoes 322 and334 on the carriage 48, or between the shoes 320 and 332 on carriage 46.It is to be noted, however, by referring to FIG. 31, that the rail 236,the shoe 332, the contacts 170, the shoe 334, and the rail 234, the shoe332, the contacts 168, the shoe 320 and the rail 234, form an electricalseries or circuit. The physical location of the shoe 320 and shoe 332 isreversed in the diagrammatic representation, FIG. 31, for the sake ofclarity.

As the reel 72 rotates, FIGS. 3 and 14, as required to bring the tape 70to the position to start the desired lesson or program, the projections132B on the belt 128 pass under the roller 314 on carriage 46 severaltimes, causing the contacts 168 to close. Since this is a seriesconnection, the circuit between the rails 236 and 232 is not completeduntil one of the projections 132A, on the belt 130 reaches the roller314A of the carriage 48, causing the contacts 170 to close,whereupon,the next time one of the projections 1328 on the belt 128causes the contacts 168 to close, the circuit between the rail 236 andthe rail 232 is completed.

When the circuit, as described above, is completed, the current from theconductor 254, through the carriages 48 and 46, as described, and intothe rail 232, whence the current passes into a conductor 342 through thewinding of the relay 344, and back to the common ground 268. The currentalso passes from the conductor 242 to a conductor 346 through thewinding of a relay 348, and back to the common ground 268. A conductor352 is connected to conductor 342 so as to energize time delay element350. With this portion ofthe circuit being completed by conductor 353which connects the time delay element to the common ground 268.

When the conductor 342 is energized, as described above, three thingshappen simultaneously. A switch portion 354 of the relay 344 breaks thecircuit through conductor 296 leading to the Stop" solenoid 290, thuspermitting the spring 292 to depress the Stop button 60 of the taperecorder 58. A switch portion 356 of the relay 348 breaks the circuitthrough conductor 300, switch 286 and conductor 302 leading to the tapeRewind" solenoid 306, or, through the circuit 304 to the Advance orForward" solenoid 310 by the respective switching action, releasing thepush buttons 64 or 68, respectively of the tape recorder 58 by suchaction. The time delay element 350 is energized to provide sufficienttime for the desired functions to be performed.

After a predetermined period of time has elapsed, the time delay element350 causes the winding of a relay 358 to'be energized by completing thecircuit from the conductors 342 and 352 through the winding of the relay358 and back to the common ground 268, FIGS. 30 and 31. Switch portions360 and 362 of the relay 358 will then be closed. Closing the switch 360energizes the coil ofa Play solenoid 364, thus causing armature 366 todepress the button 62 of the tape recorder 58. The closing of the switch362 energizes the winding of the solenoid 290 by by-passing the switchportion 354 of the relay 344, causing the armature 288 of the solenoid290 to be withdrawn, thereby releasing the push button 60 of the taperecorder 58.

The operations described above, terminate with the depressing ofthe Stopbutton 60 ofthe tape recorder 58, which marks the end of the selectioncycle. The depressing of the Play button 62, after an appropriate delayfurnished by the time delay element 350, marks the beginning of the Playcycle.

As the tape recorder 58 begins to Play," that is, the Play cycle begins,the reel 72 rotates, which causes the counters to start theirintermittent rotation, as described, and the belts 126, 128, and allbegin to move, since they are driven by the counters, drums orsprockets. As the belt 128 starts to move, the projections 1328 wouldleave the roller 314 of the carriage 46, thereby permitting the contacts168 to open, thus breaking all of the circuits described, at the end ofthe selection cycle and the beginning of the Play cycle. This wouldimmediately cause the machine to revert to the beginning of theselection cycle. To prevent this, a conductor 368 is added in the formof a loop,'in conjunction with the relay 348. The conductor or loop 368permits the power to the conductor 342 and the winding of relay 348 tobe obtained directly from the conductor 254, thereby permitting thecircuits just described to be held closed for the remainder of the Playcycle.

The number of lessons or programs included in the tape 70 may beeffectively doubled by recording 21 sep arate lesson or program on eachstereo track and utilizing the cut-out of notches 52 and 52A, FIGS. 22and 23, in the lesson selector element 2 and the channel selectorswitches 54 and 56, FIG. 31.

The audio circuit, external of the tape recorder, comprises a left handcircuit 370, which extends from the tape recorder 58 to a set ofcontacts on the selector switch 54, and a right hand circuit 372, whichextends from the tape recorder 58 to a set of contacts on the selectorswitch 56, FIG. 31. A circuit 374 extends from the second set ofcontacts on the switch 56 to a speaker 376 and jumpers 378 and 380connect the corresponding contacts of the switches 54 and 56, thusconnecting the circuit 374 to either switch. If no cut-outs or notchesare used in the lesson selector element 2, the contents of both channelswill be supplied to the speaker 376.

The visual portion of the lesson or program provided by the machinecomprises a projection system, which system projects the enlarged imageof a series of pietures upon a translucent screen 410, FIGS. 1, 8 and16, which is built into the front of the cabinet which houses themachine, thereby giving the appearance somewhat of a television screen.The pictures are provided by a series of transparencies 398, FIGS. 8,21, 27 and 29,

mounted in a laminated plastic disc which disc is rotatably mounted inthe lesson selector element 2.

By referring to FIG. 8, it is seen that the projection system comprisesa light source 384 which is cooled by a fan 386, which fan is powered bya motor 388. A condensing lens 390 is situated at the juncture of ahousing 392 and a light-tight tubev 394. A focusing lens 396 is mountedat the top of the tube 394, directly below a transparency 398, which ispermanently assembled between the laminations of a disc 400 which ispermanently assembled within the lesson selector element 2. Othertransparencies, such as 3988, 398C, etc, are also assembled within thedisc 400 in a manner identical to the transparency 398.

The portion of the projection system above the lesson selector element2, FIG. 8, comprises a transparent sealing member 402 which is locatedat the bottom of the light-tight tube 404, a mirror 406, and a system ofprojection lenses contained in a threaded tubular housing 408, whichprojects the desired image upon a translucent screen 410.

The details of the structure of the lesson selector element 2 and theassociated parts are shown in FIGS. 26, 27 and 28 and 29. The lessonselector element 2 is rectangular in shape, as shown in explodedcondition in FIG. 28. The projection 6 and an upstanding lug or stop 414are formed integrally on an upper lamination 412 of the lesson selectorelement 2. A center lamination 416 surrounds the disc 400 and a coilspring 418. A lower lamination 420 of the lesson selector element 2contains the integrally formed projections 24, 26, 28 and 30, and anadditional projection 422, which serves as a journal for the lowerportion of a hub 424 of the disc 400.

The disc 400 is oflaminated structure and comprises, in part, an upperlamination 426. The upper portion of the hub 424 and a projection 428are integrally molded on the upper lamination 426. When the lessonselector element is assembled, the projection 428 registers with theupstanding lug or stop 414. A lower lamination 430 is integrally moldedwith the lower portion of the hub 424. The transparencies 398, 3988,398C, etc. are assembled between the laminations 426 and 430 inselectively a manner whereby each transparency is in register with anopening, such as 432, 4328, 432E, etc., in the upper lamination 426, andother openings, such as 434, 434A, 434B, etc., in the lower lamination430.

The transparency to be shown is initially required to be in line with,and closest to, a stop surface 436 of the projection 428. The rest ofthe transparencies are then placed in a sequential arrangement in aclockwise direction from the transparency to be shown initially, asshown in FIG. 29. A D-shaped bore 438 through the hub 424 must also becorrectly indexed with respect to the stop surface 436.

The coil spring 418 is provided with lugs or pins 440 and 442 whichengage a hole 444 in the outer periphery of the disc 400 and a hole 446in an opening 448 of the center lamination 416, respectively, FIGS. 27and 28.

The hub 424 of the disc 400 is journaled in holes 450 lamination are inregister with the transparency 398 to be shown initially, so that thelight emerging from the lower tube 394, FIG. 8, passes through theopening 458, the opening 434, the transparency 398, the opening 432, theopening 456, FlGS. 26, 27 and 29, and into the upper tube 404, FIG. 8.

If the lesson selector card 2 is to incorporate the channel selectionfeature, the cut-out 52 or the cut-out 52A, FIGS. 22 and 23, isincluded. The lesson selector element 2, when completely assembled andready for use, houses the assembled disc 400 and the coil spring 418.The disc 400 is free to rotate within the lesson selector element 2, butthe action of the coil spring 418 causes the stop surface 436 of theprojection 428 to bear against the upstanding lug or stop 414, therebyplacing the initial transparency 398 in register with the openings 456and 458 in the upper and lower laminations 412 and 240, respectively ofthe lesson selector element 2.

The upper portion of the shaft 20 embodies a D- shaped cross-section toregister with the D-shaped bore 438 in the hub 424 of the disc 400,FIGS. 8, 21, 26 and 29. Due to the D-shape of the bore 438, FlG. 8, thedisc 400 is placed in a driven relationship with respect to the shaft20. The lower portion of the shaft 20 also embodies a D-shapedcross-section which engages a corresponding D-shaped bore in flangedsleeves 460 and 462, as will best be seen in FIGS. 8, l9 and 32. Theupper surface of the sleeve 460 serves also as a seat for the lower endof the spring 22. The shaft 20 is also provided with a collar 464 havingan upper surface which serves as a bearing surface for the arm 18, whilethe lower surface of the collar 464 serves as a shoulder for the upperend of the spring 22. A ratchet wheel 466 is retained between theflanged sleeves 460 and 462, FIGS. 8, 19 and 32, and is maintained indriving relation with the shaft 20 by the D-shaped bore which engagesthe lower portion of the shaft 20, which also embodies a D-shapedcross-section in this area.

A projection 467 is provided on the sleeve 460. The projection 467 isindexed with respect to the D-shaped bore of the sleeve in such manneras to orient the shaft 20, so that the upper D-shaped crosssection ofthe shaft passes freely through the D-shaped bore 438 in the hub 424 ofthe disc 400, when the projection 428 of the disc 400 bears against thestop 414 of the lesson selector element 2 and the projection 467 bearsagainst a pin or stop 467A in a support member or shelf 480, FIGS. 8, 19and 32.

A flexible cord 467B, FIGS. 2, 8 and 18, is attached to the cylindricalsurface of the lower sleeve 462 by suitable attaching means 467C. Atension spring 467D is affixed to the other end of the cord 467B. Thetension spring 467D is anchored to the bottom portion of a bolt or screw467E, as may best be seen in FIGS. 2, 8, 18 and 32.

An armature 468, of solenoid 470, is provided with teeth 472, whichteeth engage the teeth of the ratchet wheel 466, as shown in FIGS. 19and 32. The solenoid 470 drives the ratchet wheel 466 in acounterclockwise direction. A pawl 474 is provided to prevent rotationof the ratchet wheel 466 in the opposite direction. The armature 468 ofthe solenoid 470 is provided with stops which limit the stroke of thearmature to that required

1. A teaching machine, which machine comprises; a. a cabinet,
 1. saidcabinet having an opening formed therein to receive a rectangular lessonselector element,
 2. a visual reproduction means within said cabinet, b.a rectangular lesson selector element having abutments formedthereon,
 1. a circumferentially apertured disc rotatably mounted on saidrectangular lesson selector element and having photographictransparencies in said apertures to sequentially register with saidvisual reproduction means when said lesson selector element is insertedinto the teaching machine to project visual information from saidphotographic transparencies, c. reproduction means within said cabinethaving a plurality of lessons recorded thereon for audiblereproduction,
 1. sound reproduction means within said cabinet foraudibly reproducing a selected lesson of said reproduction means insynchronous relation with respect to said visual reproduction means, d.an electrical circuit connected with said teaching machine foractivating electrical components therein,
 1. a first sonic switch withinsaid electrical circuit to control the sequential operation of thevisual reproduction means, in coordination with said sound reproductionmeans,
 2. a second sonic switch within said electrical circuit tocontrol the operation of an audio recorder within said electricalcircuit and to close said circuit upon the cessation of the recording byan ultrasonic sound being coded onto the tape, e. ultrasonic signalscoded onto the reproduction means at selected places to initiate actionof said first and second sonic switches to open and close circuits andto deactivate the electrical circuit when the recording has beencompleted.
 2. said abutment cams are adapted to engage said switches onsaid third carriage when in one postiion to close said switches,
 2. acontact point on said arm,
 2. a visual reproduction means within saidcabinet, b. a rectangular lesson selector element having abutmentsformed thereon,
 2. a second sonic switch within said electrical circuitto control the operation of an audio recorder within said electricalcircuit and to close said circuit upon the cessation of the recording byan ultrasonic sound being coded onto the tape, e. ultrasonic signalscoded onto the reproduction means at selected places to initiate actionof said first and second sonic switches to open and close circuits andto deactivate the electrical circuit when the recording has beencompleted.
 2. A teaching machine as defined in claim 1, wherein a. saidcabinet has a plurality of walls,
 2. a speaker in a wall of said cabinetfor reproduction of the audible portion of a lesson by the audiblereproduction means,
 2. a lesson selector element to actuate theelectrical control circuit means to operate the audible and visualreproduction means to reproduce selected parts of the audibleinformation and selected visual information,
 2. a disc rotatably mountedin the hollow of said intermediate sheet and having a plurality ofopenings formed therethrough,
 2. a forward switch element within saidelectrical circuit,
 3. a reverse switch element within said electricalcircuit,
 3. A teaching machine, which machine comprises; a. areproduction means having information recorded thereon for audiblereproduction, and sound reproducing means for audible reproduction of aselected part of the information recorded thereon, b. visualreproduction means for projecting visual information from photographictransparencies, c. control means for controlling the operation of theaudible reproduction means and the visual reproduction means toselectively reproduce audible information in synchronization,
 3. aphotographic transparency mounted in selected openings of said disc, e.said sheets which enclose said disc having openings formed therein whichare in aligned relation and adapted to register with openings in saiddisc, when each of said openings in said disc is moved to a selectedposition, to enable the projection of visual information of saidtransparencies by the visual reproduction means.
 3. circuit operatingelements on said lesson selector element for actuating circuitcomponents, d. said lesson selector element comprising upper, lowr andintermediate sheets of rigid material,
 3. a wall of said cabinet havingan opening formed therein for admitting said rectangular lesson selectorelement having abutments thereon to close at least one said switch andto bring the initial aperture containing a transparency into registerwith the visual reproduction means, to enable a selected disc to projecta visual portion of the lesson onto the screen in synchronized sequencewith the audible reproduction means,
 3. said switches each havingcontact point on each said downwardly extending projection and contactpoints on said third carriage, so upon said projections engaging saidabutment cams said contact points will be closed to form a circuitthrough said switches to cause power means, which operate said soundreproduction means, to drive said sound reproduction means one way oranother so as to bring said lesson into a reproduction position.
 3. acontact point on said second carriage so upon said downwardly extendingarm engaging said abutments a circuit is closed through said points tocause said sound reproduction means to initiate movement of said firstand second endless members until a preprogrammed lesson is moved intoproper position for reproduction of a portion of a sound track and toproject photographic transparencies onto said translucent screen. 4.sonic switch elements within said electrical circuit, k. said lessonselector element having abutments formed thereon to actuate saidstarting switch element and to close said forward switch element or toclose said reverse switch element to selectively start the sequentialprojection of said transparencies onto said translucent screen andfurther to start said sound reproduction means in synchronized relationwith said transparencies, and to progressively move said transparenciesout of register with said visual reproduction means and to sequentiallymove other transparencies into register therewith to present apreprogrammed lesson as determined by one of said switching elements, 4.a further abutment on said rectangular lesson selector element to closea switch to initiate movement of the audible reproduction means in onedirection or in the opposite direction to bring the audible reproductionmeans into proper synchronization with the visual reproduction means. 4.A teaching machine as defined in claim 3; wherein a. said lessonselector element has a notch formed in one edge thereof to aCtuate oneof the electrical circuit components of the circuit control means, andb. the lower sheet of rigid material of the lesson selector element hascircuit operating projections extending therefrom to actuate other ofthe circuit components.
 5. A teaching machine as defined in claim 4;wherein a. said lesson selector element has access means providedtherein for entry into the hollow thereof, to enable replacement of thedisc containing the transparencies for visual reproduction.
 6. Ateaching machine as defined in claim 4; wherein a. the circuit operatingprojections extending from the lower sheet of rigid material of saidlesson selector element are differently positioned on other lessonselector elements to control the operation of selected circuitcomponents to different extents to selectively control the operation ofthe audible reproduction means.
 7. A teaching machine as defined inclaim 3; wherein a. the disc of said lesson selector element has a hub,which hub has a non-circular bore formed therein, b. the visualreproduction means includes a drive shaft, which drive shaft is of thesame cross-sectional configuration as the bore of the hub of the disc ofthe lesson selector element, c. said upper and lower sheets, of rigidmaterial of said lesson selector element, each has an aperture formedtherethrough, which apertures are in alignment so as to journal the hubof the disc therein,
 8. A preprogrammed teaching machine, which machinecomprises; a. a housing, b. sound reproduction means within saidhousing, c. a visual reproduction means within said housing, d. atranslucent screen mounted in said housing to receive visualreproductions, e. a plurality of guideways within said housing, f. aslot formed within a wall of said housing to be in register with one ofsaid guideways to receive a lesson selector element therein, g. arectangular lesson selector element, having abutments formed thereon,which element is adapted to be inserted through said slot in saidhousing into one of said guideways, h. photographic transparenciesmounted within said lesson selector element and being adapted toregister with said visual reproduction means, when in one position, i.means for succesively moving said photographic transparencies into andout of register with said visual reproduction means sequentially, j.electrical circuits associated with said teaching machine,
 9. A teachingmachine as defined in claim 8; wherein a. a carriage is movably mountedon another of said guideways, which carriage has contact switch pointsthereon to selectively form a circuit, b. means on said lesson selectorelement engageable with said carriage to move said carriage along saidguideway to a predetermined position, c. a gear element connected indriven relation with said sound reproduction means, d. an idler gearpositioned a spaced distance from said gear element, e. an endlessmember surrounding said gear element and said idler gear in drivingrelation, and f. spaced apart cam abutments on said endless member toengage said switch on said carriage to close said contact switch pointswhen one of said cam abutments on said endless member engages saidswitch to bring the proper preprogrammed lesson into position toreproduce sound in synchronized relation with said photographictransparencies transmitted onto said translucent screen.
 10. A teachingmachine as defined in claim 9; wherein a. a second carriage is mountedin another of said guideways, b. a second gear element is connected indriven relation with said sound reproduction means, c. a second idlergear is positioned a spaced distance from said second gear element, d. asecond endless member surrounds said second gear element and said secondidler gear in driving relation, e. spaced apart abutment cams on saidsecond endless member,
 11. A teaching machine as defined in claim 10;wherein a. a third carriage is mounted in one of said guideways, b. aplurality of switches mounted on said third carriage, c. a third gearelement is rotatably mounted within said housing and is connected indriven relation with said sound reproducing means, d. an idler gear isrotatably mounted a spaced distance from said third gear element, e. athird endless drive member surrounding said third gear element and saidthird idler gear in driving relation, f. abutment cams on said thirdendless member,
 12. A preprogrammed teaching machine as defined in claim8; wherein a. said lesson selector element has projections thereon toselectively actuate a forward or reverse switch element to bring saidsound reproduction means and said visual reproduction means intosynchronized relation to reproduce a preprOgrammed lesson.
 13. Apreprogrammed teaching machine as defined in claim 12; wherein a. saidprojections on said lesson selector element are selectively positionedto cause different programs to be brought into position for thereproduction thereof, when each of the lesson selector elements is fullyinserted into said guideway.
 14. A preprogrammed teaching machine asdefined in claim 12; wherein a. an abutment of each said lesson selectorelement, b. latch means within said teaching machine housing which isengageable with said abutment when said lesson selector element isproperly inserted in said guideways so said lesson selector element isheld in a selected position until the lesson has been reproduced, and c.means for releasing said latch means to enable another lesson selectorelement to be moved into said guideways.